A cordless drill is the most important power tool you’ll buy. It’s the one you’ll rely on for big projects, such as building a deck and remodeling a kitchen, and for smaller tasks, like installing fixtures and assembling furniture. You might even need your drill to service other tools.
Most cordless drills these days run on lithium-ion (Li-ion) batteries, which deliver more power and longer run times in a lighter package than before. According to the Natural Resources Defense Council, Li-ion batteries have improved so much over the past decade that a newer drill might run 50 percent longer than a drill from seven years ago.
Many of today’s cordless drills also benefit from a motor makeover. Not long ago, brushless motors (as opposed to the more prevalent brushed variety) were reserved for contractor-oriented brands such as DeWalt, Makita, and Milwaukee, but now they’re available in modestly priced consumer drills from the likes of Kobalt, Porter-Cable, and Ridgid.
Unlike brushed motors that run at the same rate whether you’re drilling into a softwood, such as pine, or a hardwood, like oak—thereby draining the battery—brushless motors adjust to the level of resistance they encounter and use up less energy. Plus, they operate with less friction than brushed motors, allowing them to work more efficiently. They also have fewer moving parts, and because they have no brushes, you never need to think about replacing them.
We conduct all our performance testing on a benchtop dynamometer, or “dyno,” a calibrated instrument featuring a free-spinning spindle and an electronic brake. CR’s test engineers clamp each drill onto the spindle, then run it flat out at each speed, measuring maximum revolutions per minute, or RPM. These results, along with measurements taken under different loads, determine the speed score.
To calculate run time, we cycle the batteries on and off to simulate a torturous slew of stop-and-go tasks, such as building a deck. Then we completely drain each battery and time how long it takes it to recharge. And of course we use the dyno to measure torque and RPMs, which we translate into our power score. This test is a reflection of how big a hole a drill can bore, or how large a fastener it can drive.
After the calibrated tests, CR’s experts use each drill to drive screws and drill holes like you would, taking note of aspects such as balance, feel, and ease of adjusting the chuck and speed, and assign each model a score for handling. Finally, we measure sound in decibels at the user’s ear to get a score for noise. As it turns out, all but the smallest models require hearing protection for safe use.
See below for advice on how to choose the best drill for you.
Before you compare individual models, you’ll want to narrow your search based on what voltage drill you want. That’s an indication of power. Keep in mind, though, that while an 18- or 20-volt cordless drill might be more powerful than a 12-volt model, it’s also bulkier. Today’s 12-volt drills can easily drive a few hundred decking screws on a single charge and are probably all the power the typical homeowner needs. But they wouldn’t be your first choice for driving large lag bolts. For that you’d want a stout 18-volt model, which can also drill into brick or concrete block.
We divide our cordless drill ratings into three categories based on how you might use the drill: heavy-duty, general-use, and light-duty. Manufacturers don’t market drills this way, so we use chuck size to categorize our test models. What’s a chuck? The three-pronged clamp that secures bits at the business end of any drill. It takes both cutting bits for drilling holes and driving bits for screwing in fasteners. The greater a drill’s chuck’s capacity, the bigger the bit it can hold and, typically, the more power the model will have. Which is to say, chuck size is a good proxy for how heavy-duty a drill is.
Models in our heavy-duty category are those with a ½-inch chuck, the largest size you’ll find on cordless models. General-use drills have a ⅜-inch chuck and can handle the bulk of bits you’ll probably need. Our light-duty drills typically have a fixed, ¼-inch socket, a design that accepts only bits with a hex-shaped shaft.
Drills in this category are built around brawny 18- to 24-volt batteries, giving them the power to drive large fasteners and bore holes through thick boards. Outfitted with ½-inch chucks, they can accept most any drill bit, including those used for jobs like drilling into brick or concrete block. All that capability means heavy-duty drills tend to be the most expensive and heaviest. So before you buy, you’ll want to hold one with the battery clipped in place to see how it handles.
Most people will be best served by one of these ⅜-inch chuck models. Typically powered by a 12-volt battery, they’re more powerful than they look: They can bore holes in wood with relative ease and drive a pouch full of screws on a single charge. And if you keep one battery charging while you’re working, you can always swap in a fresh one and never run out of juice. If you need to take on the occasional heavier job, you can always rent a hammer drill from a home center.
This eclectic class of drills is best-suited for small jobs around the house: assembling flat-packed furniture, changing a light fixture, and drilling into drywall. Their batteries range in size from 12 volts to 20 volts, but their relatively small motors don’t spin or drive with the same force as heavy-duty or general-use drills. Further limiting their use, they have a fixed, ¼-inch socket designed to accept only ¼-inch hex bits. Still, they’re nice to have around the house.
CR’s experts assign each model a score for handling, but that quality can be a personal thing. A drill should feel good in your hand.
So before buying a new one, clip in the battery and grip it to see how it handles and whether you can tolerate the weight for longer jobs. Wield it above your head, as if you were installing a smoke detector, and you’ll notice right away if it feels too heavy.
Some general-use drills have a pistol grip, with a cylindrical battery buried in the handle, and they are quite comfy to grasp. But with no flat battery at the base of the handle, they don’t stand upright on their own, so you’ll need to decide whether it will drive you crazy to have to lay down your drill between uses.
Cordless drills are sold in three configurations:
1) As a standalone tool with one or two batteries and a dedicated charger
2) As part of a collection of cordless tools from a single brand, called a kit
3) As a bare tool, with no battery or charger
If you want only a drill and don’t own any other power tools with compatible batteries, go for option 1. If you’re also in the market for tools such as an impact driver, a circular saw, a reciprocating saw, and a work light, consider the kit, which will give you the most value. (Just know that kits typically feature 18-volt tools, so the included drill would be a heavy-duty model.) Kits often come with two batteries and a charger. If you already have a compatible battery from a different cordless tool, a bare drill (option 3) will suffice. Option 3 is the least expensive but the worst value.
Here are five cordless drill features that are important to consider.
Most cordless drills come with either a ½-inch or a ⅜-inch chuck. The size tells you two important things about a drill. First, it provides an upper limit for the shank size of the bits the drill can accommodate. Bigger bits often have wider shanks, so a heavy-duty paddle bit that you’d use for mixing grout or joint compound wouldn’t fit into a drill with a small chuck. Second, chuck size also tracks closely to a drill’s power and capability—more powerful drills usually have larger chucks and vice versa.
Early Li-ion batteries often needed to be charged and used under precise conditions to ensure peak performance. But the newest generation of batteries and chargers prevents overcharging batteries, alleviating the need to drain them fully between charges to ensure the longest possible life. New chargers also include an indicator light, which clearly displays how close the battery is to a full charge. Some brands also have indicator lights on the batteries themselves.
Li-ion batteries for cordless power tools have two important specs. Voltage correlates roughly to power. An 18-volt drill will be more powerful than a 12-volt drill from the same brand. But a 14.4-volt drill from one brand may be less powerful than a 12-volt tool from another. (Check out the power score in CR’s Cordless Drills ratings for a true comparison.) Amp-hours indicates how much fuel the battery contains, which translates to run time. A 4.0-amp-hour battery should run twice as long as a 2.0-amp-hour battery—but it’s also twice as heavy. And because some batteries charge in as little as 25 minutes, you might prefer two smaller batteries.
Brushless motors reduce friction and sense resistance from the work material, continually adjusting the amount of power they draw from the battery. Manufacturers say this translates to longer run times, more power, and a longer product life. In CR's cordless drill tests, the top six heavy-duty models all feature brushless motors, as does the top-performing general-use drill—the only 12-volt drill with a brushless motor tested. Warranties indicate manufacturers' confidence in brushless technology: three to five years on the new tool vs. just three for the older technology. We think that makes brushless a smarter buy.
Almost all cordless drills come with a built-in LED work light, a single Phillips bit, and extras such as belt clips and hard-sided cases. A few brands stand out for extra features. Milwaukee offers chargers capable of charging its 12- and 18-volt batteries at the same time—nice if you own a drill of each type. And Porter-Cable makes an LED flashlight that runs on one of its 20-volt batteries.